Drafting mechanism



June 14, 1960 P. B. TARBOX 2,940,130

DRAFTING MECHANISM Filed June 25, 1958 2 Sheets-Sheet 1 June 14, 1960 P. B. TARBOX DRAFTING MECHANISM 2 Sheets-Sheet 2 Filed June 25, 1958 Fig.5

United rates Patent DRAFTING MECHANISM Philip B. Tar-box, Saco, Maine, assignor to Saco-Lowell Shops, Boston, Mass, a corporation of Maine Filed June 25, 1958, Ser. No. 744,452

8 Claims. (Cl. 119-131) This invention relates to drafting mechanisms of the type used on spinning and roving frames and the like, and more particularly, to novel positioning and weighting structures for the upper drafting elements of drafting mechanisms of the type wherein a short upper apron cooperates to perform the drafting function with a long lower apron having an apron supporting roll and apron bar within its loop.

In any mechanism of this type, a major problem is that of maintaining the upper drafting elements in proper parallel alinement with their cooperating bottom rolls since, if the parallel relationship is disturbed to such an extent that the m's of a top roll and a bottom roll no longer lie in a common plane, then the lineal contact between the two rolls becomes shortened and the drafting operation becomes erratic and generally unsatisfactory. This problem is particularly troublesome in drafting mechanisms wherein capbars are employed for locating the upper drafting elements, since parallelism is lostvas the capbar bearing slots become worn with use, or as the capbar tips may be improperly set.

Accordingly, the present invention is directed to a novel positioning and weighting structure for upper drafting elements of the short apron types in which none of the elements is supported by capbars and in which at least certain of the elements including the front roll and, in

some instances the rear roll, are allowed freely to swing transversely sufficiently to permit their self-alinement with their cooperating bottom rolls, the structure carrying the short upper apron preferably being positioned by the apron bar. Supplementary weighting means are also provided preferably in the form of a saddle and link structure cooperating with the front roll positioning structure to weight all of the top rolls against their bottom rolls.

It is a feature of the invention that the apparatus provided is readily adapted for use on existing types of spinning or roving frames, and Without utilizing their generally worn capbars, so that the advantages of the invention, including especially the self-alinement of front rolls, may be realized.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a view, mainly in vertical section, showing a drafting mechanism embodying this invention;

Figs. 2, 3 and 4 are cross-sections of portions of the mechanism of Fig. 1 taken, respectively, on the lines 2-2, 33, and l-l thereof; and t Fig. 5 is a plan view or" the mechanism shown in Fig. 1.

Referring to the drawings, the drafting mechanism of the invention in general includes a pair of front or delivery rolls, an intermediate fiber control mechanism for feeding and controlling a strand of discontinuous fibers such as cotton roving or sliver, and behind the fiber control mechanism a pair of rear or holding rolls. The fiber control mechanism itself includes a a lower unit an endless underlying fiber supporting lower apron 20 having within its loop a lower apron driving roll 22, an apron bar 2A- and apron tension roll23. Its upper unit includes an apron cradle having side members 40 and a tensor 42 extending therebetween, said cradle positioning an overlying roll and the overlying short apron 30 encircling said rolland tensor. The lower rolls, the delivery roll 12, the holding roll 16, and the lower apron driving roll 22 extend for the entire length of the spinning frame and are conventionally driven by gearing located in the end thereof. The top delivery roll, top holding roll, and top control roll are each of the two-boss type wherein a pair of bosses are rotatively mounted on a normally non-rotating arbor. Thus, the top delivery roll includes bosses 14 and arbor 15 and the top holding roll bosses 18 and arbor 19. The bosses 34 of the top control roll are mounted on arbor 36 which is itself positioned at each end thereof in suitable recesses 44 in apron cradle side members 4%). Suitable bearings are provided between the bosses and the arbor of each of the top rolls.

The short upper apron 30 overlies the lower apron 20 to cooperate therewith to control a strand as it passes between the aprons, both of the aprons being nipped to drive them between the apron driving roll 22 and the overlying upper roll. The apron cradle includes side members 40 spaced to fit adjacent the sides of a boss 34 to limit lateral movement of the overlying roll, and an apron tensor 42 having a rounded forward apron engaging edge extending between said side members at the forward portion of the cradle inside the loop of upper apron 39, the tensor 42 normally being positioned above apron bar 24 and being the sole transverse structural member extending between said side pieces. Legs 41 are provided on said side members extending'downwardly ther from for engagement with cooperating slots 25 providing recesses in apron bar 24, such legs serving to-snpport and aline the cradle relatively to the apron bar 24, preferably to position the overlying middle roll, apron and tensor solely with reference to the apron bar and by contact of the overlying middle roll with its cooperating roll 22 through aprons 29 and 3%. The cradle, together with a boss 34 on the overlying roll, supports and guides the upper apron 3-9, the side members 4% of said cradle also functioning to guide the upper apron 39 to prevent lateral movement thereof with respect to the cradle. The recesses 4-4 provided on the rear edge of side members 40 engage the rotatively fixed arbor 36 of the upper roll, while the apron 3t encircling a boss 34 and a tensor 42, firmly and r siliently, but removably, holds the cradle and roll together, maintaining them in assembled relation both on and off the frame. The forward end of the cradle is made self-s acing to provide an accurate vertical clearance between the tensor and the lower apron bar'24 by means of a suitable lug, such as a machine screw 48 mounted. on the apron tensor 42 between the roll bosses with the head thereof extending downwardly.

According to the present invention-the intermediate fiber control mechanism including the short upper apron 30 and its roll being positioned relatively to the apron bar as above described-the front top roll isallowed freely to swing transversely sufliciently to permitits selfalinement with its cooperating bottom roll, and the rear top roll may alsobe allowed a degree of freedom for such self-alining movement, but preferably is accurately supported in relation to its cooperating bottom roll. To accomplish this preferred result, the rear top roll is supported between its bosses 18 centrally of its arbor 19 at the forward end of a forwardly extending arm 52 mounted at its rear end on a cylindrical support bar 50 itself suitably mounted on the machine frame. The mounting of said arm 52 on said bar 50 is preferably by means of'accurately alined bores on the spaced downturned sides '53 of said arm, such as to permit swinging movement in a vertical plane. If desired,1the mounting may be such as to permit a limited amount of transverse swinging movement for self-alinernent; for example, by enlarging slightly the diameter of the bores in sides 53; 'Ifhe for:

, ward end of arm 52 has an upturnedportion 54 for receiving the arbor 19 of the rear top roll, as well as a spring 56. The front top roll supporting arm 60 is piv-' otally mounted on the rear top roll supporting .arm 52 by means of a pivot pin 62 which engages a cooperating horiiontaltplane for self-alining movement vof the, front top roll and to position said front top roll. Recesses 66 are provided at the forward end of arm.60 for engagement l I p apron mounted above and contacting said lower apron with arbor 15 centrally thereof between bosses 14, as well as a spring 68, for removably retaining the arbor in saidrecesses. 7 r a For weighting the toprolls, a saddle 70 is provided extending between the central portion of the arbor 19 of the rear roll 18 and the top of cradle arm 46 extending upwardly from tensor 42 centrally thereof between its adjacent inner side members"a suitable cut-out being provided in the upturned portion 54 of arm 52 to prevent interference.

' saddle 70 with the forward end offront roll top arm60,

' weighting hook 90 mounted on link 80 by a shaft 86 positioned between pins 82 and 84, said book being weighted by any suitable means (not shown) The weighting hook isarranged to be easily removable so that theentire top roll to position said front top roll, a rear weighting saddle extendingbetween said cradle and said rear top rolls, a link connecting said rear weighting saddle extending forwardly of said rear saddle. and connected to said front top roll-supporting arm, and weighting means pressing downwardly on said link to press said top rolls against their corresponding bottom rolls.

2. A drafting mechanism of 'the character described including frontfr'niddle and rear sets of devices for feeding and controlling a strand of vdiscontinuous fibers, said sets being arranged: one in advance of the other to act successively on a'strand,'the front and rear sets of said devices comprisingbottom rolls and overlying top rolls and the middle set of said devices comprising an endless underlying strand supporting lower apron having within its loop a lower apron driving roll, an apron bar forward of said apron driving roll and an apron tensioning roll below said apron driving roll, and an endless overlying and having within its loop an overlying apron roll and an apron cradle tensor member forward of said overlying apron roll, said overlying roll and said cradle tensor member being mounted at their ends on cradle side mem bers providing laterally spaced projections for engaging cooperating laterally spaced recesses on said apron bar to removably position said overlying middle roll, apron and tensor solely with referenceto said apron bar and by A link 80 is provided totloosely connect contact of said overlying middle roll with said underlying middl'eroll through said aprons, a rear top roll supporting assembly of arm 60 with its top roll 14 can be easily removed from the spinning frame for cleaning or removing lap-nps. The back top roll 18 and its arm 52 may be swung vertically about support rod 50 for access as for cleaning or changing top rolls.- Thereafter,

the cradle assembly may-be removed by lifting it out of its apron bar slots 25, and it may then be readily taken apart if desired for changing aprons or rolls or for more complete cleaning, the tension of apron 30 normally serving to hold the cradle assembly together.

arm mounted centrally of said rear roll, a front top roll supporting, arm mounted centrally of said front roll, said ,front top roll supporting arm being pivotally mounted on said rear top roll supporting arm for swinging movement in a horizontal plane for self-alining movement of said front top roll to position said front top roll, and weighting means pressing downwardly on said top rolls to press said top'rolls against theircorresponding bottom rolls. '3. A drafting mechanism, of the'character described including front, middle and rear sets of devices for feeding and controlling a strandof'discontinuous fibers, said sets being arranged one in advance of the other, to act successively on a strand, the front and rear sets of said devices comprising bottom rolls and overlying top rolls and the middle set of said devices. comprising an endless underlying strand supporting lower apron having within its loop a lower apron driving roll, an apron bar 7 forward of said apron driving roll and an apron tension- Thus, the invention provides a novel and simple ar- 7 rangement for positioning and weighting drafting assemscope of the appended claims will be apparent to those 7 side members providing laterally spaced projections for skilled in this art.

I claim: t l. A drafting mechanism of the character described ineluding from, middle and rear sets of devices for feeding sets being arranged one in advance of the other to act successively on astrand, the front and rear sets of said devices comprising bottom rolls and overlying top rolls and the middle set of said devices comprisingan endless underlying strand supporting lower apron having within its loop a lower apron roll, 'an apron bar forward of said apron driving roll and an apron ftensioning roll below said apron driving roll,fand an endless overlying apron mounted above and contacting saidlower apron 'roll supporting arm being pivotally mounted on said rear top roll supporting arm for swinging movement in a .hOfi ntal plane'for self-alining movement of said front "and controlling a strand of discontinuous fibers, said ing roll below said' apron driving roll, and an endless overlying apron mounted above and contacting said lower apron and having within its loop an overlying'apron roll and an apron cradle tensor member forward of said overlying apron roll, said overlying roll and said cradle tensor member beingrmounted at their ends on cradle engaging cooperating, laterally spaced recesses on said apron bar to removably position said overlying middle roll, apron and tensor solely with reference to said apron bar and by contact of said overlying middle roll with said underlying middle roll through said aprons, a rear top roll supporting arm mounted centrally of said rear roll, a front top roll supporting arm mounted centrally of said front roll, said front top roll supporting arm being pivotally mounted on said rear top roll supporting arm for swinging movement in a horizontal plane for selfaliniug movement of said front top roll to position said front top roll, a rear weighting saddle extending between said cradle and said rear top rolls, a link connecting said rear weighting saddle extending forwardly of said rear saddle, and connected to said front top roll supporting arm,.and weighting means pressing downwardly on said link to presssaid top rolls against their, corresponding bottom rolls. a r t e 4. A drafting mechanism, of the character described including front, middle and rear sets of devices for fccdsets being arranged one in advance of the other to act successively on a strand, the front and rear sets of said devices comprising bottom rolls and overlying top rolls and the middle set of said devices comprising an endless underlying strand supporting lower apron having within its loop a lower apron driving roll, an apron bar forward of said apron driving roll and an apron tensioning roll below said apron driving roll and an endless overlying apron mounted above and contacting said lower apron and having within its loop an overlying apron roll and an apron cradle tensor member forward of said overlying apron roll, said overlying roll and said cradle tensor member being mounted at their ends on cradle side members providing laterally spaced projections for engaging cooperating laterally spaced recesses on said apron bar to removably position said overlying middle roll, apron and tensor solely with reference to said apron bar and by contact of said overlying middle roll with said underlying middle roll through said aprons, a rear top roll supporting arm mounted centrally of said rear roll, cylindrical bar means pivotally mounting said rear top roll supporting arm rearwardly of said rear top roll for swinging movement in a vertical plane, a front top roll supporting arm mounted centrally of said front roll, said fiont top roll supporting arm being pivotally mounted on said rear top roll supporting arm rearwardly of said rear top roll for swinging movement in a horizontal plane for self-alining movement of said front top roll to position said front top roll, a rear weighting saddle extending between said cradle and said rear top rolls, a link connecting said rear weighting saddle extending forwardly of said rear saddle and connected to said front top roll supporting arm, and weighting means pressing downwardly on said link to press said top rolls against their corresponding bottom rolls.

5. A drafting mechanism as claimed in claim 4 wherein said rear top roll' supporting arm is mounted on said cylindrical bar means in alined relation therewith for positive alinement of said rear top roll.

6. A drafting mechanism as claimed in claim 4 wherein said rear top roll supporting arm is mounted on said cylindrical bar means for swinging movement in a horizontal plane for self-alining movement of said rear top roll.

7. A drafting mechanism of the character described including front, middle and rear sets of devices for feeding and controlling a strand of discontinuous fibers, said sets being arranged one in advance of the other to act successively on a strand, the front and rear sets of said devices comprising bottom rolls and overlying top rolls and the middle set of said devices comprising an endless underlying strand supporting lower apron having within its loop a lower apron driving roll, an apron bar forward of said apron driving roll and apron tensioning means, and an endless overlying apron mounted above and contacting said lower apron and having within its loop an overlying apron roll and an apron cradle tensor member forward of said overlying apron roll, a rear top roll supporting arm mounted centrally of said rear roll, a front top roll supporting arm mounted centrally of said front roll, said front top roll supporting arm being pivotally mounted on said rear top roll supporting arm for swinging movement in a horizontal plane for self-aligning movement of said front top roll to position said front top roll, a rear weighting saddle extending between said cradle and said rear top rolls, a link connecting said rear weighting saddle extending forwardly of said rear saddle and connected to said front top roll supporting arm, and weighting means pressing downwardly on said link to press said top rolls against their corresponding bottom rolls.

8. A drafting mechanism of the character described including front, middle and rear sets of devices for feeding and controlling a strand of discontinuous fibers, said sets being arranged one in advance of the other to act successively on a strand, said devices including bottom rolls and overlying top rolls, a rear top roll supporting arm mounted centrally of said rear roll, a front top roll supporting arm mounted centrally of said front roll, said front top roll supporting arm being pivotally mounted on said rear top roll supporting arm for swinging movement in a horizontal plane for self-aligning movement of said front top roll to position said front top roll, a rear weighting saddle extending between said middle and rear top rolls, a link connecting said rear weighting saddle extending forwardly of said rear saddle and connected to said front top roll supporting arm, and weighting means pressing downwardly on said link to press said top rolls against their corresponding bottom rolls.

References Cited in the file of this patent UNITED STATES PATENTS 2,246,474 Stahlecker June 12, 1941 

